Stacking is a technique by which multiple semiconductor dies (chips) or multiple semiconductor packages are stacked on one another to reduce the overall package footprint and size. In the case of chip-on-chip stacking technology, two semiconductor dies are attached to one another in a stacked arrangement with bond wire connections to the dies. The stacked chip arrangement with wire bond connections is then molded to form the final package. However, with the chip-on-chip stacking approach, both dies are fully encapsulated by the mold compound, limiting the thermal performance of the final solution. Also, dedicated wire bond design rules are required to form the bond wire connections to the stacked die arrangement. In the case of package-on-package stacking technology, two fully completed semiconductor packages are stacked on one another. That is, each semiconductor package has been molded, trimmed and formed prior to stacking. The finished packages are then glued to one another in a stacked arrangement. However, with the package-on-package stacking approach, both packages are fully molded and the dies are embedded entirely within the respective mold compounds, again limiting the thermal performance of the final solution.
Hence, there is a need for improved stacked assemblies for packaging semiconductor devices.